Reference Standard
1) Purity:
- Exceptionally high purity (often exceeding 99.9%)
- Minimizes margin of error for comparison with other materials.
2) Characterization:
- Rigorously characterized through extensive testing Determines exact chemical and physical properties (e.g., structure, melting point. IR, Purity, etc.,) Serves as a definitive reference point for comparison.
3) Source:
- Obtained from reputable external sources.
- Examples: Pharmacopeias (USP, BP), Certified Reference Material (CRM) providers,Ensures objectivity and consistency across different laboratories.
4) Use:
Serves as the ultimate benchmark for quality control Used for:
- Calibration of analytical instruments.
- Validation of analytical methods (ensuring accuracy, precision, reliability).
- Quality control testing (verifying drug substances/products meet specifications).
5) Calibration:
- Not routinely calibrated.
- Maintains its exceptional purity due to limited use.
- Sets the gold standard for purity and characterization.
- Provides the ultimate authority for calibrating and verifying working standard.
6) Analogy:
- Master key for accurate analysis.
- Defines the definitive properties of a material.
Working Standard
1) Purity:
- Good purity (typically above 95%).
- Meets specific quality control requirements for routine analysis.
2) Characterization:
- Validated in-house to ensure reliable results for specific uses.
- May not require the same level of detail as a reference standard.
3) Source:
- Derived from reference standards.
- Often prepared by dilution or calibration of a reference standard.
- More readily available for frequent use within a lab.
4) Uses:
- Daily calibration of analytical instruments (maintaining accuracy without depleting reference standards).
- Intermediate checks and in-process controls during manufacturing.
- Cost-effective alternative for frequent testing.
5) Calibration:
- Requires regular calibration against the reference standard.
- Ensures accuracy is not compromised through use or storage.
- Frequency of calibration depends on specific use and stability of the working standard.
6) Analogy:
- Key copy used to frequently open the door for routine analysis.
- Requires verification with the master key (reference standard) to ensure continued accuracy.
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Resource Person: Saravanan Paramasivam
